The so-called bad debts are mainly caused by loan business. If the loan cannot be recovered, it will become dormant account and bad debt. The five major banks started loan business earlier. At that time, the banking industry had little experience in loan business and the internal control measures were not perfect. As a result, a large number of loans turned into bad debts. The loan business of Postal Savings Bank only started in 2008, because it started late. We have fully absorbed the experience and lessons of the same industry, and have a set of scientific and strict system and methods in internal control and target customer selection, and have zero tolerance in loan business, so the assets of the Postal Savings Bank are excellent.